1. Field of the Invention
The present invention relates to a data recording method for recording photographic data in an IC memory during photography, and on a magnetic recording layer formed on a filmstrip. The present invention relates also to a lens-fitted photo film unit having a data recording device for recording photographic data in an IC memory during photography.
2. Background Arts
A new type photo film cartridge, called IX 240 type or Advanced Photo System type, has recently been put on the market. The IX 240 type film cartridge contains a photo filmstrip having a transparent magnetic recording layer, as is disclosed in December 1994 issue of SHASHIN KOGYO, p.11, published by Shashin Kogyo Shuppan Co. Ltd., International Patent Publication WO 90/04214, and so forth. The magnetic recording layer is used to record photographic data or the like which is produced by the camera, and read it to utilize for printing and other purpose.
The photographic data written on the magnetic recording layer may include exposure data such as shutter speed, aperture size and light source, print format data designating one of standard, panoramic and cine size. If the camera has a device to designate a trimming or clopping range, as disclosed in JPA 54-26721, the trimming range may be included in the print format data. Also, date data or optional character data for printing the date of photograph or the title or comments in addition to the photographed scene.
The photographic data can be read out in a photo-lab. For example, the exposure data is utilized for controlling exposure in printing. The print format data is utilized for automatic setting of the print magnification, the film mask and the paper mask, so that it is possible to automatically make prints in the different formats according to the photographer's request even when the original frames on the filmstrip have a constant size. Since the date data or the character data read out from the magnetic recording layer makes it possible to photographically print character information on the photo paper concurrently with the image printing, those optical data recording devices incorporated in conventional cameras are not necessary. The character data may include data of printing position, printing posture, printing size and printing color, so that it can innovate in the optical data recording for photo-prints.
Camera type data on the magnetic recording layer may be utilized for determining whether print-exposure correction is necessary or not. Recording number-of-print data with such a frame from which a known plural number of prints are to made, permits obtaining the necessary number of prints immediately after the development, so that the photographer need not order extra printing. The magnetic recording layer may be used for recording data in the photo-lab, such as the number of extra prints, print-exposure correction data, and the reception date and reception number of print order.
For the magnetic recording on the photo film, the camera must have a magnetic recording device comprised of a magnetic head and a magnetic head driving circuit. Because the photo film is certainly stiffer than ordinary magnetic audio or video recording tapes, it is necessary to support the magnetic head or the photo film in a specific fashion to maintain the head in proper contact with the magnetic recording layer during the recording. Moreover, because the magnetic recording should be accomplished while the photo film is advanced one frame after each exposure at changeable or unstable speed, it is necessary to adjust the data recording speed to the film advancing speed. Accordingly, the magnetic head driving circuit have to be complicated and expensive.
For the reasons as above, it is commercially impossible to incorporate a magnetic recording device for the photo film into economy type cameras or single-use cameras including lens-fitted photo film units preloaded with unexposed photo film. Hereinafter, the lens-fitted photo film units will be referred to as film units. Without the magnetic recording, the photographer cannot make the best of the IX 240 type film cartridge, though the IX 240 type is preferable for the compact cameras and the film units because it is smaller and lighter than conventional film cartridges.
On the other hand, JPA 56-154720 and JPA 2-217829 disclose a photo film cartridge with an IC memory or semiconductor memory, and a system for recording photographic data as above in the IC memory so as to permit the photographer or the photofinisher to utilize the photographic data. This IC memory system functions substantially in the same way as the above magnetic recording system, and the cost can be lower than the magnetic recording system. Accordingly, it has been studied to introduce the IC memory system into the cheap cameras and the film units.
For example, a data recording circuit for recording data in the IC memory may be provided on the same printed circuit board as the flash circuit of the film unit, and may be supplied from the battery for the flash circuit. In that case, however, it is necessary to wire from the data recording circuit on the flash circuit board to a data recording terminal in a cartridge chamber, to access the IC memory of the photo film cartridge. Wiring is so hard to automate, that it would require manual assembly steps, and raise the manufacturing cost of the film unit. Since the flash circuit board is determined to be reused, the circuit board must be easy to dissemble even if it has the data recording circuit connected to the IC memory. Furthermore, the wiring from the flash circuit board to the cartridge chamber should not remarkably enlarge the size of the film unit.
There is another problem in the IC memory system. Once the photo film is separated from the cartridge shell with the IC memory, it is impossible to correlate the photo film with the photographic data written in the IC memory. For correlation, JPA 2-217829 discloses recording identical or corresponding indicia on both the photo film and the cartridge shell. If the indicia on the photo film or the portion having the indicia is damaged, the correlation becomes impossible. Also, it is necessary to correlate the respective frames on the photo film with the photographic data with reference to other indicia provided for indicating the position or the serial number of each frame, such as notches or bar code.
JPA 4-306628 discloses a film unit attached with a date memory device for storing the date of photographing in an IC memory such as SRAM or EEPROM. The date memory device is removable from the film unit, and includes a clock section and a control section besides the IC memory. The date memory device and the used photo film cartridge are removed from the film unit in the photo-lab. The exposed photo film is developed, and the date memory device is set in a specific photo printer along with the corresponding photo film, so that the date data is read from the IC memory, to print the date of photography in an appropriate position of the photo paper in association with each image. Alternatively, the date of photography is optically recorded on the photo film before development, based on the date data written in the IC memory. Thereby, the date of photography will always be printed with the image.
It may be possible to provide a memory device in the film unit to write not only date data but also other photographic data in an IC memory of the memory device. However, it is hard to optically record all pieces of photographic data on the photo film before development. Therefore, it is desirable to permit recording the photographic-data read from the IC memory on the magnetic recording layer of the photo film.